This SAE Recommended Practice is applicable to pneumatic Passenger Car “P” Type, Light Truck Metric, and Light Truck High Flotation tires, or similar tires approved by bodies other than Tire & Rim Association. The methodology is applicable within normal operating ranges of vertical load and inflation pressure, and for velocities between 115 km/h and 15 km/h (71 mph and 9 mph) during a relatively short duration event such as a coastdown. This procedure is applicable only to operation in the free-rolling mode at zero slip and camber angle for ambient temperatures between 20 °C and 28 °C (68 °F and 82 °F) and for surfaces with diameters of 1.2 m (48 in) diameter or greater. Details regarding the equipment, tires, and test methods used specifically for validation of this document are included in Appendix A.
The revisions in this version are to address missing SI units a typo in section 3.10 and to clarify issues associated with zero speed points in the MERF/SMERF calculations.